For the banh mi:
For the carrot pickle:
Make the carrot pickle first so it has time to pickle overnight. Shred the daikon and carrot in a food processor using the medium disc, or shave them into fine ribbons with a peeler, a sharp knife or a mandolin.
Stir together sugar and warm water until the sugar is dissolved, add the vinegar and pour the liquid to cover the vegetables. Leave the pickle in the fridge overnight.
To make the butter mayo, crack the eggs into a bowl, beat them with a hand mixer, slowing adding the oil with the mixer running until it thickens and looks like soft butter. (The trick here is to add the oil nice and slow in a thin stream; adding too much at once will make it split.)
Now to put it all together. When you’re ready to eat, cook the steaks and egg.
Heat a small pan over a medium heat. (If you have a barbecue or another way you prefer to cook steak, go for it.) Season the steaks well with salt and pepper then fry in the pan with a little oil for 2 minutes on each side (or till they’re cooked how you like them), then remove them from the pan to rest
While the steaks are resting, add more oil to the pan and fry the eggs sunny side-up till the edges are crisp.
To assemble your sandwiches, cut the banh mi lengthways and spread the base with butter mayo and the pâté. Slice the steaks across the grain and add them to the banh mi followed by the egg, cucumber, pickles, coriander, chillies and spring onion. Season with soy sauce, salt and pepper. Enjoy!